In a manufacturing process for manufacturing semiconductor devices, liquid crystal panels, LEDs, solar cells or the like, a process gas is introduced into a process chamber which is being evacuated to perform various processes such as an etching process, a CVD process or the like. The process chamber for performing various processes such as an etching process, a CVD process or the like is evacuated by a vacuum pump. Further, the process chamber and exhaust apparatuses connected to the process chamber are cleaned periodically by supplying a cleaning gas thereto. Because exhaust gases such as the process gas, the cleaning gas or the like contain a silane-based gas (SiH4, TEOS or the like), a halogen-based gas (NF3, ClF3, SF6, CHF3 or the like), a PFC gas (CF4, C2F6 or the like) or the like, such exhaust gases have negative effects on human bodies and on the global environment such as global warming. Therefore, it is not preferable that these exhaust gases are emitted to the atmosphere as they are. Accordingly, these exhaust gases are made harmless by an exhaust gas treatment apparatus provided at a downstream side of the vacuum pump, and the harmless exhaust gases are emitted to the atmosphere.
In a manufacturing process for manufacturing semiconductor devices, liquid crystal panels, LEDs, solar cells or the like, various process gases, a cleaning gas and the like are used. The exhaust gas treatment apparatus for treating exhaust gases such as various process gases and a cleaning gas, has the following problems.
1) Specifications of the exhaust gas treatment apparatuses are prepared for respective customers and respective processes depending on the kinds (reactions) of the gases and the gas flow rates to be used in the semiconductor manufacturing processes, and the exhaust gas treatment apparatuses are evaluated and then brought to the market. In this case, in order to treat the exhaust gas to an allowable concentration or smaller, a treatment part, a cooling part, a powder collection part and the like are customized (modified depending on the specifications). Therefore, the exhaust gas treatment apparatuses need to be designed, manufactured and evaluated, for respective customers and respective manufacturing processes, thus requiring a great deal of labor and increasing an apparatus cost.
2) A process apparatus generally comprises one or more process chambers, and one or more dry vacuum pumps are connected to each process chamber, and then respective exhaust lines of the dry vacuum pumps are connected to the exhaust gas treatment apparatus. Therefore, the exhaust gas treatment apparatus needs to treat exhaust gases from the plural process chambers. Since the respective plural process chambers differ in recipes, the kinds of gases to be used and the timing of inflow of the gas differ in the respective process chambers. Accordingly, when taking into consideration the kind of gas and the pattern of the amount of gas to be introduced into the exhaust gas treatment apparatus, innumerable combinations can exist. The exhaust gas treatment apparatus having treatment performance which can deal with all these combinations is demanded, resulting in excessive performance (over-engineering).
3) Since the exhaust gases are introduced into the exhaust gas treatment apparatus from the process apparatus operated by using plural chambers, the treatment capacity of the exhaust gas treatment apparatus depends on the use conditions. Therefore, it is necessary to select hardware settings, utility settings and software settings of the exhaust gas treatment apparatus to fit the use conditions or to cover the assumed use conditions, and thus it is difficult to cope with change of the recipe and change of the process flexibly and promptly.
4) It is common for the specifications of the exhaust gas treatment apparatus to collectively treat exhaust gases from the plural chambers by the single abatement apparatus, and thus the exhaust gas treatment apparatus inevitably becomes large in size. In many cases, the large exhaust gas treatment apparatus is installed at a place apart from the dry vacuum pump by a certain distance due to limitations of the installation place in the factory. In a process in which a product is generated, if an exhaust line is long, the product is liable to accumulate. Therefore, maintenance of the exhaust line is necessary to affect downtime of the process apparatus. The accumulation of the product increases back pressure of the dry vacuum pump and causes a pump trouble.
5) In order to suppress the generation of sublimation product, it is necessary to install a heater on a pipe of the exhaust line, thus affecting an initial cost, a running cost, and the installment work time of the heater. The restoration of the heater at the time of the maintenance of the exhaust line also affects a process downtime.
6) The heater installed on the pipe generally employs a jacket-type heater which has a heater coil therein. The monitoring of the temperature necessary for controlling the heater is performed by a thermocouple provided on the heater coil or on a surface of a piece of an object to be heated. Since the unevenness of temperature distribution of the object to be heated cannot be avoided by single-point temperature control, in order to make the temperature distribution as uniform as possible, a large amount of design work such as feedback of measured results or re-manufacturing is required. Further, when the heater is installed on a long pipe, segmentation of the heater or the like is generally necessary to make the temperature distribution uniform, and thus complex individual control and complex wiring of the segmentalized heater are required. Consequently, an increase of labor of installation work, an increase of the initial cost and the like are caused.
7) The dry vacuum pomp for exhausting the process chamber and the exhaust gas treatment apparatus are individually controlled. Specifically, ON/OFF of the operation, switching of a combustion mode, interlock and the like are performed by exchanging signals individually between the dry vacuum pump and the manufacturing apparatus and between the exhaust gas treatment apparatus and the manufacturing apparatus. Accordingly, input and output signals need to be controlled with respect to each of the dry vacuum pump and the exhaust gas treatment apparatus. Further, the monitoring of the dry vacuum pump and the exhaust gas treatment apparatus is performed individually to control the operations of the dry vacuum pump and the exhaust gas treatment apparatus. Therefore, when protocols which work in conjunction with the manufacturing apparatus are constructed in each of the dry pump and the exhaust gas treatment apparatus, the manufacturing apparatus needs not only complex control hardware/software design but also complexly constructed wiring, thus causing an increase of design man-hours of the manufacturing apparatus. As a result, not only the initial cost but also verification time increases.